A bone density test is mainly to determine if you have osteoporosis. Osteoporosis is a disorder characterized by bones that are more fragile and more likely to break.
Before now, osteoporosis would be suspected only after you broke a bone, as your bones could be quite weak, but bone density test enhances the accuracy of calculating your risk of breaking bones.
A bone density test uses X-rays to measure how many grams of calcium and other bone minerals are packed into a segment of your bone. The bones that are most commonly tested are the bones of the spine, hip and sometimes the forearm.
Most people have no bone loss or have a mild bone loss (osteopenia), and as such, their risk of breaking a bone is low; so they do not need the test. They should, however, exercise regularly and get plenty of calcium and vitamin D, which is the best way to prevent bone loss.
Why Bone Density Test is done
Doctors use bone density testing to identify decreases in bone density before you break bones. They also use it to determine your risk of broken bones (fractures) and to confirm a diagnosis of osteoporosis.
Bone density test is utilized to monitor osteoporosis treatment, since the higher your bone mineral content, the denser your bones are, and denser bones equal stronger bones that are generally less likely to break.
Bone density tests differ from bone scans as no injection is used beforehand. Bone scans require an injection beforehand and are usually used to detect fractures, cancer, infections and other abnormalities, underlying in the bone.
Osteoporosis is more common in older women, but men also can develop the condition. Your doctor or health caretaker may recommend a bone density test if you show the following signs:
- Lost height, as a result of compressed fractures in their spines, for which osteoporosis is one of the main causes.
- Fractured a bone, which can occur when a bone becomes so fragile that it breaks much more easily than expected. In some cases, fragility fractures can sometimes be caused by a strong sneeze.
- Long-term use of steroid medications, such as prednisone, can interfere with the bone-rebuilding process, and that can lead to osteoporosis.
- Transplant: People who have received an organ or bone marrow transplant are at higher risk of osteoporosis. This is partly because; anti-rejection drugs also interfere with the bone-rebuilding process.
- Had a drop in hormone levels as a result of the natural drop in hormones that occurs after menopause, or hormone drop during certain cancer treatments.
Who Should Get A Bone-Density Scan?
Women should get a bone density scan at age 65, and men age 70 and up, and you may want to talk with a medical expert about the risks and benefits before deciding.
Similarly, younger women and men ages 50 to 69 should consider the test if they have risk factors for serious bone loss. Such risk factors include:
- Breaking a bone in a minor mistake or accident
- Having rheumatoid arthritis.
- Having a close relative who broke a hip from a minor accident
- Smoking and drinking heavily.
- Having a low body weight.
- Using corticosteroid drugs, and
- Having disorders associated with osteoporosis.
Most bone scans use a technology called DEXA (for dual energy X-ray absorptiometry), where a person lies on a table while a technician aims a scanner mounted on a long arm. DEXA test uses very low energy radiation, and currently is the easiest, most standardized form of bone density testing.
The DEXA scanner uses beams of very low-energy radiation to determine the density of the bone, and the test is painless and considered completely safe.
Pregnant women should not get DEXA scans because the baby shouldn’t be exposed to radiation, no matter how low the dose.
Measurements are typically taken at the hip, and the spine and other sites. Insurance or Medicare generally pays for the test in some cases.
Other less commonly used technologies to measure bone density include:
- Variations of DEXA, which measure bone density in the forearm, finger, or heel.
- Quantitative computed tomography (QCT), which provides more detailed images than DEXA.
- Ultrasound of the bones in the heel, leg, kneecap, or other areas.
Risks of Bone Density Test
- Differences in testing methods
- Limited insurance coverage, as not all health insurance plans pay for bone density tests.
- Lack of information about the cause, being that a bone density test can confirm that you have low bone density, but it can’t tell you the cause. To answer that question, you need a more complete medical evaluation.
- A bone-density test gives out a small amount of radiation, but the effects can add up in your body over your life.
Results of Bone Density Test
Your bone density test results are reported in two numbers: T-score and Z-score.
Your T-score is your bone density compared with what is normally expected in a healthy young adult of your sex
|T-score||What your score means|
|-1 and above||Normal bone density|
|Between -1 and -2.5||Your score is a sign of osteopenia, which is a condition in which bone density is below normal and may lead to osteoporosis.|
|-2.5 and below||Your bone density points out that you likely have osteoporosis.|
Your Z-score is the number of standard deviations above or below what’s normally expected for someone of your age, sex, weight, and ethnic or racial origin. If your Z-score is significantly higher or lower than the average, it may suggest that there is something else, other than aging that is causing the abnormal bone loss.
How You Can Keep Your Bones Strong
The best exercise for your bones is an exercise that makes your bones carry weight, like walking and weightlifting. Aim for at least 30 minutes of weight-bearing exercise a day.
Calcium And Vitamin D
Getting enough calcium and Vitamin D helps keep your bones strong and you should aim for at least 1,200 mg of calcium a day. Eat foods high in calcium, such as dairy products, leafy green vegetables, and sardines/salmon. You may need a calcium pill each day and should consider taking vitamin D as well. Take 800 IU a day.
Avoid Smoking And Alcohol Consumption
Smoking and drinking alcohol can expose you to many health problems and can speed up bone loss. Try a stop-smoking program, and ask your health care provider about a nicotine patch or similar treatments.
Avoid Certain Drugs
Some drugs that include proton pump inhibitors (omeprazole, lansoprazole, and pantoprazole), used to treat heartburn; corticosteroids; and some of the newer antidepressants can all affect bones. Ask your health care provider about whether these medications are right for you if you use any one of these drugs.